Fluorinated imide compounds (fluorine-containing imide compounds) are known to be useful substances as anionic sources of ion conducting material or ionic liquid. Ionic liquid is particularly useful as an electrolyte, reaction solvent, catalyst or the like in batteries and capacitors. This ionic liquid is generally known to be obtained by the base exchange of, for example, salt of fluorine-containing sulfonyl imide acid which is a fluorinated imide compound, and halide salt of quaternary amines such as imidazolium bromide salt.
As methods of manufacture of fluorine-containing imide compounds, the methods described in Non-Patent Document 1 and Patent Documents 1-3 are known. Specifically, Non-Patent Document 1 discloses a method wherein, as shown in the following formula (A), fluorosulfonic acid (FSO3H) and urea ((NH2)2CO) are reacted, and the generated bis(fluorosulfonyl)imide (FSO2)2NH and excess fluorosulfonic acid are recovered by reduced-pressure distillation under heating.[Chemical formula 1]3FSO3H+CO(NH2)2→(FSO2)2NH+NH4HSO4+HF+CO2  (A)
Patent Document 1 discloses a method wherein perfluoroalkylsulfonamide (RfSO2NH2; Rf is a perfluoroalkyl group) is converted to salt of Na, K, Li or the like, and this is reacted with disulfuryl fluoride ((FSO2)2O) or sulfuryl fluoride halide (SO2FX; X is a halogen atom).
Patent Document 2 discloses a method wherein, as shown in the following formula (B); perfluoroalkyl sulfonamide (RfaSO2NH2), perfluoroalkyl sulfonyl halide (RfbSO2X), and a fluorine compound (MF) such as potassium fluoride are reacted with an organic solvent such as acetonitrile to produce perfluoroalkyl sulfonyl imide salt ((RfaSO2)(RfbSO2)N.M).[Chemical formula 2]RfaSO2NH2+RfbSO2X+4MF→(RfaSO2)(RfbSO2)N.M+2MFHF+MX  (B)
In said formula (B), Rfa and Rfb indicate perfluoroalkyl groups or the like, M indicates alkali metal or the like, and X indicates fluorine or chlorine, respectively.
Patent Document 3 discloses a method wherein, as shown in the following formula (C), perfluoroalkyl sulfonamide and perfluoroalkyl sulfonyl halide are reacted in the presence of a tertiary amine or heterocyclic amine (NR1R2R3) to produce perfluoroalkyl sulfonyl imide salt ((RfcSO2)(RfdSO2)N.R1R2R3NH).[Chemical formula 3]RfcSO2NH2+RfdSO2X+2NR1R2R3→(RfcSO2)(RfdSO2)N.R1R2R3NH+R1R2R3NHX  (C)
In said formula (C), Rfc and Rfd indicate perfluoroalkyl groups or the like, and R1 to R3 indicate alkyl groups or the like, respectively.